V4: clean-up target specific register definitions and stack usage

All constants referring to registers and all constants and functions
that do platform specific things with the stack, are all modev into a
separate file. Information about how a specific platform register is
used by the ABI is also extended and is now captured in the RegisterInfo
class. Usage of this information will be extended in subsequent patches.

This also fix ARM register usage:
- Correct fp register for Thumb mode.
- Only push registers that have to be saved and will actually be used
  from the stack (i.e. do not push r0-r3 in the function prelude).

Change-Id: Ia372505ade8f2648595c7aec1d281955392f34a1
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/qml/jit/qv4registerinfo_p.h b/src/qml/jit/qv4registerinfo_p.h
new file mode 100644
index 0000000000..b9bef678a3
--- /dev/null
+++ b/src/qml/jit/qv4registerinfo_p.h
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4REGISTERINFO_P_H
+#define QV4REGISTERINFO_P_H
+
+#include <QtCore/QString>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace JIT {
+
+class RegisterInfo
+{
+public:
+    enum { InvalidRegister = -1 };
+    enum SavedBy { CallerSaved, CalleeSaved };
+    enum RegisterType { RegularRegister, FloatingPointRegister };
+    enum Usage { Predefined, RegAlloc };
+
+public:
+    RegisterInfo()
+        : _reg(InvalidRegister)
+        , _type(RegularRegister)
+        , _savedBy(CallerSaved)
+        , _usage(Predefined)
+    {}
+
+    RegisterInfo(int reg, const QString &prettyName, RegisterType type, SavedBy savedBy, Usage usage)
+        : _reg(reg)
+        , _prettyName(prettyName)
+        , _type(type)
+        , _savedBy(savedBy)
+        , _usage(usage)
+    {}
+
+    bool isValid() const { return _reg != InvalidRegister; }
+    template <typename T> T reg() const { return static_cast<T>(_reg); }
+    bool isCallerSaved() const { return _savedBy == CallerSaved; }
+    bool isCalleeSaved() const { return _savedBy == CalleeSaved; }
+    bool isFloatingPoint() const { return _type == FloatingPointRegister; }
+    bool isRegularRegister() const { return _type == RegularRegister; }
+    bool useForRegAlloc() const { return _usage == RegAlloc; }
+
+private:
+    int _reg;
+    QString _prettyName;
+    RegisterType _type;
+    SavedBy _savedBy;
+    Usage _usage;
+};
+typedef QVector<RegisterInfo> RegisterInformation;
+
+} // JIT namespace
+} // QV4 namespace
+
+QT_END_NAMESPACE
+
+#endif // QV4REGISTERINFO_P_H